1. Field of the Invention
The present invention is generally related to a cooling water distribution system for a marine propulsion device and, more particularly, to a manifold having a perforate surface shaped to conform to the inner surface of a primary cooling water conduit of an outboard motor.
2. Description of the Prior Art
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
Marine propulsion devices typically utilize lake or sea water as a cooling liquid to remove heat from various heat producing components of an internal combustion engine. Some of the cooling water, induced to flow through a cooling system of the engine by a water pump, is diverted to accessory components or devices which allow the operability of the cooling system to be monitored. Since cooling water is drawn from a body of water in which a marine vessel is operated, debris can be drawn through the cooling conduits of the marine propulsion device. Therefore, various techniques are usually employed to avoid the blocking of small cooling channels with the debris.
U.S. Pat. No. 6,036,556, which issued to Baker et al on Mar. 14, 2000, describes an outboard motor with a bleed system for an engine cooling jacket. A jet propulsion unit comprises a housing including a wall defining a water tunnel having therein a water outlet port. It also comprises a recess located in the wall defining the tunnel and in surrounding relation to the port. It further comprises a screen located at the recess and extending across the port and in flush relation to the wall defining he tunnel.
U.S. Pat. No. 4,160,733, which issued to Nelson on Jul. 10, 1979, describes a marine engine cooling water filter cleaning system. The invention pertains to an engine installation using marine water as a coolant and having an intake conduit system for draining marine water to the engine including a strainer at the inlet and a filter between the strainer and the water pump. To clean the filter and strainer which periodically becomes clogged with foreign matter while the engine is operating, a valve mechanism is provided between the filter and the water pump which is operative to close the conduit to the pump and to admit compressed air to the filter side of the valve mechanism for a short time to blow back the clogging material from the filter and strainer to the sea. In a semi-automatic embodiment the valve mechanism is a solenoid operated 3-way valve which is preferably operated from the pilot house for a short interval of about 10 seconds when the boat operator observes an above normal engine temperature. In an automatic embodiment a heat sensor associated with the engine energizes the solenoid circuit when a predetermined above normal temperature is reached and a cycle timer in the circuit controls the solenoid operation through predetermine ON and OFF periods.
U.S. patent application Ser. No. 10/142,772, which was filed by Jackson on May 13, 2002, describes an installation for recovering debris stopped by a filter at the inlet of a heat exchanger. An installation for recovering debris stopped by a filter at the inlet of a heat exchanger comprises a washing water manifold at the outlet of the filter which feeds a separator provided with an outlet pipe for water free of debris to which is connected an ejector nozzle which is connected to the outlet pipe of the exchanger.
It would be significantly beneficial if a cooling water distribution system could be provided in which a single perforate surface can be used to prevent the flow of debris into a plurality of water conduits, in which each of the plurality of water conduits directs a portion of the cooling water flow to various auxiliary devices and/or regions of the internal combustion engine. It would also be significantly beneficial if the perforate surface can be shaped to conform to a primary coolant passage in order to minimize the adverse effects of debris and weeds flowing through the primary coolant passage while reducing the effect on the flow of water through the primary passage.
A cooling water distribution system for a marine propulsion device, made in accordance with the preferred embodiment of the present invention, comprises a housing structure, a cavity formed within the housing structure, and a perforate surface of the housing structure in which the perforate surface is shaped to be inserted into an opening formed in a water conducting cavity of the marine propulsion device. The present invention further comprises a first water conduit connected in fluid communication with the cavity and a second water conduit connected in fluid communication with the cavity.
The perforate surface comprises a plurality of holes in which each of the plurality of holes is smaller in dimension, such as diameter or area, then either of the first and second water conduits. The perforate surface is curved to generally conform with an inner surface of the water conducting cavity. The housing structure is shaped to dispose the perforate surface in a non-protruding position, in relation to an inner surface of the water conducting cavity, when the housing structure is attached to a portion of the marine propulsion device in which the water conducting cavity is contained and the perforate surface is disposed in fluid communication with the water conducting cavity.
The first water conduit is connectable to a fuel cooling system. The second water conduit is connectable to an exhaust cooling system. The present invention can further comprise a third water conduit that is connected in fluid communication with the cavity. The third water conduit is connectable to a tell-tale system. The perforate surface is a curved surface having a radius of curvature which is generally equal to a radius of curvature of an inside surface of the water conducting cavity surrounding the perforate surface.